Block from U+FFF0 to U+FFFF. This block was introduced in Unicode version 1.1 (1993). It contains 7 codepoints.
The Wikipedia provides the following information on block Specials:
Specials is a short Unicode block of characters allocated at the very end of the Basic Multilingual Plane, at U+FFF0–FFFF. Of these 16 code points, five have been assigned since Unicode 3.0:
U+FFF9 INTERLINEAR ANNOTATION ANCHOR, marks start of annotated text
U+FFFA INTERLINEAR ANNOTATION SEPARATOR, marks start of annotating character(s)
U+FFFB INTERLINEAR ANNOTATION TERMINATOR, marks end of annotation block
U+FFFC  OBJECT REPLACEMENT CHARACTER, placeholder in the text for another unspecified object, for example in a compound document.
U+FFFD � REPLACEMENT CHARACTER used to replace an unknown, unrecognised, or unrepresentable character